Press



29, 1931. F.- x. HOPPER 1,838,835

- PRESS Filed Nov. 19, 1927 2 She'ets-Sheet 1 I IN V EN TOR.

L) I BY W A TTORNEYS. I

F. x. HOPPER 1,838,835

Dec. 29, 1931.

PRESS 2 Sheets-Sheet 2 Filed Nov. 19; 192? INVENTOR.

ATTORNEYS.

Patented Dec. 29, 1931 UNITEDVSTATES r'RANZ'XAVER HOPPER, or Annnrrz, AUSTRIA Panes 7 Application filed November 19, 1927. Serial No. 234,492.

This invention relates to presses adapted for use with plastic material such as celluloid and the like. One object of the invention is to produce a press of light weight and of small dimensions which will be capable of' appear from the following specification and claims.

Referring to the drawings:

Fig. 1 is a side elevation of my improved press, partly in median section;

Fig. 2 is an end elevation thereof; and

Figs. 3 and 4 are transverse sections through the press showing the pressing surfaces respectively closed and open.

The press is mounted upon a base 10, presenting a pressing surface 11 upon which the material to be pressed, either alone or enclosed within a mold, is placed. At the ends of this base are formed guides 12 in which run vertically movable side bars 13. At their upper ends these bars are bent as at 14 to embrace a pressinghead 15 which is screwed thereto at 16. This head bears a pressing surface '17 coacting with the surface 11 formed on the base. The lower ends of the bars are bent as at 18 to embrace a cross bar 19 to which they arescrewed as at 20. V In each of the bars 13 is formed a slot 21 furnishing vertical bearing for the shaft 22 of V a roll 23. Grooves 24 are formed at the ends of the shaft 22 so that it may be engaged by a suitable wrench for rotating the roll.

Positioned respectively above and below the roll and in frictional contact therewith are two wedges 25 and 26 with their slanting surfaces extending in opposite directions. Above the wedge 25 are rollers 26 which maybe of the conventional roller-bearing type separated by the usual cage (not shown).. These rollers bear against an abutment 28 secured'in any suitable manner to the base 10.

Below the wedge 26 are rollers 29 similarly bearing against an abutment 30 secured to the cross bar 19. Springs 31 strained between the crossbar 19 and fixed points on the base. exert a constant tendency holding the cross bar, the side bars 13, and the head 12 upwardly. i

In use, the material to be pressed is laid upon the surface 11 when the press is open as in Fig. 4. By means of a wrench applied to one or both ends of the shaft 22, the roll 23 is then rotated in the direction of the arrow in Fig. 4. This causes the wedges to be moved in opposite directions by reason of their frictional contact with the surface of roll 23. As the'wedges are drawn toward the position of Fig. 3 the cross bar is forced down an amount equal to twice the vertical component of either wedge. This movement of the cross bar likewise draws down the side bars 13 and the head 15 and causes pressure to be exerted between the surfaces 11 and 17. At the same time the roll is moved downwardly an amount equal to half the motion of the head; or in other words, an amount equal to the'vertical component of wedge 25. 'The wedges are preferablyflattened at their thickerends so that,

as clearly shown in Fig; 3, a definite limit will be set to the closing movement of the press and'the press will be locked in this position. V i i What I claim is:

' 1. A'heavy duty press for molding plastic material such as "celluloid, comprising a frame, a stationary press head supported by the frame, a second press head mounted in the frame for movement toward and from the first, a pair of bearing members, one mounted on the frame and the other connected to the second press head for movement therewith, said bearing members presenting parallel bearing surfaces of large area facing towards each other, a cyllnder mounted in the frame between the bearing members for'rotation and for transverse motion along a line connecting. the two bearing surfaces, a series of anti-friction bearing rollers located in rolling contact with the bearing surface of each of said members,

and a pair of oppositely tapering wedges each having a flat side in contact with one of said series of bearing: rollers and a slanting slide of slight inclination in line contact with said cylinder, whereby when the cylinder is rotated the wedges will be shifted on their bearing rolls and the press heads moved towards each other with a heavy pressure.

2. A heavy duty press for molding plastic material such as celluloid, comprising a frame, a stationary press head supported by the frame, a second press head mounted in the frame for movement towards and from the first, a pair of bearing members, one mounted on the frame and the other connected to the second press head for movement therewith, said bearing members presenting parallel bearing surfaces of large area facing towards each other, a cylinder mounted in the frame between the bearing members for rotation and for transverse mo tion along a line connecting the two bearing surfaces, aseries of anti-friction bearing rollers located in rolling contact with the bearing surface of each of said members, and a pair of oppositely tapering wedges each having a flat side in contact with one of said series of bearing; rollers and its opposite side in line contact with the cylinder and formed with a slanting surface terminating in an area parallel to its flat side, whereby when the cylinder is rotated the wedges will be shifted on their bearing rolls and the press heads moved towards each other with a heavy pressure during the contact of the cylinder with the slanting surfaces of the wedges and when the cylinder contacts with the 1 zrallel areas the press will be locked in a predetermined closed position.

3. A heavy duty press for molding plastic material such as celluloid, comprisinga frame, a stationary press head supported by the frame, a second press head located above the first, side members mounted for vertical reciprocation in the frame and connected to the second press head, springs normally holding the side members and the second press head in elevated position, a pair of bearing members, one mounted on the frame and the other positioned below the first and connected to the said side members, members presenting parallel bearing surfaces of large area facing towards each other, a cylinder mounted in the frame between the bearing members for rotation and for transverse motion along a line connecting the two bearing surfaces, a series of antifricticn bearing rollers located in rolling}; contact with the bearing surface of each of said members, and a pair of oppositely tapering wedges each having a fiat side in contact with one of said series of bearing rollers and a slanting side of slight inclination in line contact with said cylinder, whereby said 

